TWI532814B - Manufacture of adhesive sheet and electronic parts - Google Patents

Description

Adhesive sheet and method for manufacturing electronic parts

The present invention relates to an adhesive sheet and a method of manufacturing an electronic component using the same.

A semiconductor wafer is bonded to an adhesive sheet after forming a circuit, and then cut into a component sheet (cut), washed, dried, stretched (expanded) of the adhesive sheet, and self-adhesive sheet peeled component sheet (picked), Assembly and other processes. The adhesive sheet (cut tape) used in these processes has sufficient adhesion to the cut component sheet (wafer) from the dicing step to the drying step, but it is desirable to reduce the adhesion to no during the picking process. Adhesive deposits appear.

As the adhesive sheet, there is a layer of an adhesive which is subjected to a polymerization curing reaction by ultraviolet ray or the like on a substrate which is transparent to an activating light such as ultraviolet ray and/or an electron beam. As for the adhesive sheet, the method is as follows: after the cutting process, ultraviolet ray or the like is irradiated to the adhesive layer, and the adhesive layer is cured by polymerization to lower the adhesive force, and then the cut wafer is picked up.

As such an adhesive sheet, Patent Document 1 and Patent Document 2 disclose an adhesive sheet formed by applying an adhesive to a surface of a substrate, the adhesive containing, for example, a three-dimensional network by activating light. A compound (polyfunctional oligomer) having a photopolymerizable unsaturated double bond in the molecule.

Further, Patent Document 3 discloses an adhesive sheet for semiconductor processing by coating an adhesive layer composed of a base polymer, a radiation polymerizable compound, and a radiation polymerizable polymerization initiator on a substrate surface. Layers are formed.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. SHO 60-196956

[Patent Document 2] Japanese Laid-Open Patent Publication No. 60-223139

[Patent Document 3] Japanese Laid-Open Patent Publication No. 2002-285134

In the semiconductor wafer processing step, when the good and defective products are screened by testing the performance of the semiconductor wafer on which the circuit is formed, the semiconductor wafer may be heated. Further, when the cutting water in the dicing step is removed, the semiconductor wafer is also heated.

In the case where such heating of the semiconductor wafer is performed, the adhesive layer of the adhesive sheet may be softened by heating, and the adhesive sheet may be excessively adhered to the semiconductor wafer. If the adhesive sheet is excessively adhered to the semiconductor wafer, curing the adhesive layer even if it is irradiated with ultraviolet ray or the like does not sufficiently lower the adhesive force of the adhesive layer, and causes a problem such as difficulty in picking up or deposit of the adhesive or the like.

Accordingly, it is a primary object of the present invention to provide an adhesive sheet which is difficult to produce softening of the adhesive layer upon heating.

The present inventors have found that the softening of the tackifying resin contained in the adhesive is a main cause of softening of the adhesive layer upon heating.

Based on this knowledge, the present invention provides an adhesive sheet which is attached to a substrate. A photocurable adhesive layer which forms the photocurable adhesive layer, and comprises a (meth) acrylate copolymer, a photopolymerizable compound, and a polyfunctional isocyanate curing agent. a polyfluorene-based graft copolymer and a photopolymerization initiator, which does not contain a tackifying resin, and the substrate is formed of a propylene-based copolymer which is a copolymer of propylene, 1-butene and ethylene. The (meth) acrylate copolymer is a copolymer of ethyl (meth)acrylate, butyl (meth)acrylate and methoxyethyl (meth)acrylate, and the polyfunctional isocyanate curing agent contains three or more. When the photopolymerization initiator is heated at a temperature elevation rate of 10 ° C /min from 23 ° C to 500 ° C, the temperature loss rate is 10% at a temperature of 250 ° C or higher, and the photopolymerizable compound has four The above-mentioned vinyl acrylate acrylate oligomer, and the photopolymerizable compound is 5 parts by mass or more and 200 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer, and the above polyfunctional isocyanate curing agent is relative to (A) base) 100 parts by mass of acrylate-based copolymer 20 parts by mass 0.5 parts by mass or less, the photopolymerization initiator with respect to 20 parts by mass of (meth) acrylic acid ester copolymer 100 parts by mass 0.1 part by mass or less based. Since the adhesive sheet does not contain a tackifying resin in the adhesive, softening of the adhesive layer does not occur even in the case of heating.

The adhesive sheet is preferably used by being attached to the electronic component in the inspection process of the electronic component.

Moreover, the present invention provides an adhesive for forming an adhesive layer laminated on a substrate in an adhesive sheet attached to the electronic component in an inspection process of an electronic component, characterized in that: Acrylate copolymerization a material, a photopolymerizable compound, a polyfunctional isocyanate curing agent, a photopolymerization initiator, and a polyfluorene-based graft copolymer, which do not contain a tackifier resin, and the substrate is formed of a propylene-based copolymer, and the propylene-based copolymer is Copolymer of propylene, 1-butene and ethylene, copolymerization of the above (meth) acrylate copolymer with ethyl (meth) acrylate, butyl (meth) acrylate and methoxy ethyl (meth) acrylate The polyfunctional isocyanate curing agent contains three or more isocyanate groups, and when the photopolymerization initiator is heated at a temperature increase rate of 10 ° C /min from 23 ° C to 500 ° C, the temperature loss rate is 10% and the temperature is 250 ° C. In the above, the photopolymerizable compound is an urethane acrylate oligomer having four or more vinyl groups, and the photopolymerizable compound is contained in an amount of 5 parts by mass or more and 200 parts by mass based on 100 parts by mass of the (meth) acrylate copolymer. In the following, the polyfunctional isocyanate curing agent is used in an amount of 0.5 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer, and the photopolymerization initiator is 100 parts by mass based on the (meth) acrylate copolymer. 0.1 quality The amount is 20 parts by mass or less.

Moreover, the present invention provides a method of manufacturing an electronic component, comprising: a heating process of heating an electronic component to which an adhesive sheet is bonded to 60 to 150 ° C, wherein: as the adhesive sheet, a substrate is used. An adhesive sheet formed by laminating a layer of a photocurable adhesive layer formed of a propylene-based copolymer which is a copolymer of propylene, 1-butene and ethylene, and which forms the photocurable adhesive The photocurable adhesive of the agent layer comprises a (meth) acrylate copolymer, a photopolymerizable compound, a polyfunctional isocyanate curing agent, a photopolymerization initiator, and a polyfluorene-based graft copolymer, and does not contain a tackifying resin. The above (meth) acrylate copolymer is (meth) acrylate B a copolymer of an ester, a butyl (meth)acrylate and a methoxyethyl (meth)acrylate, the polyfunctional isocyanate curing agent comprising three or more isocyanate groups, and the photopolymerization initiator is from 23 ° C to 500 ° C When the temperature is raised at a temperature increase rate of 10 ° C /min, the temperature loss rate is 10% and the temperature is 250 ° C or higher, and the photopolymerizable compound is an acrylamide ester oligomer having four or more vinyl groups, and the photopolymerizability is obtained. The compound is 5 parts by mass or more and 200 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer, and the polyfunctional isocyanate curing agent is 0.5 parts by mass or more and 20 parts by mass based on 100 parts by mass of the (meth) acrylate copolymer. In the following, the photopolymerization initiator is 0.1 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer.

In the method of manufacturing an electronic component, the heating process for the performance test may be performed at least one of the steps before and after the cutting process. That is, the method of manufacturing the electronic component may include a bonding step of bonding the adhesive sheet to a semiconductor wafer or a substrate and an annular frame, and a heating step of bonding the semiconductor to which the adhesive sheet is bonded The wafer or substrate is mounted on a table at 60 to 150 ° C to bring the adhesive sheet into contact with the table, heated by adsorption and inspection, and the semiconductor wafer or substrate is inspected; and the cutting process is applied to the adhesive. a semiconductor wafer or a substrate after the sheet is cut as a semiconductor wafer or a semiconductor component; a light irradiation step of irradiating the photocurable adhesive layer of the adhesive sheet with activating light; and an expanding step of widening the semiconductor wafer or the semiconductor component The adhesive sheet is stretched at intervals therebetween, and a pick-up process is performed to pick up the semiconductor wafer or the semiconductor component from the adhesive sheet. Moreover, the manufacture of the electronic component The method may further include a bonding step of bonding the adhesive sheet to a semiconductor wafer or a substrate and an annular frame, and a dicing step of cutting the semiconductor wafer or substrate to which the adhesive sheet is attached a semiconductor wafer or a semiconductor component; a heating process in which a semiconductor wafer or a semiconductor component to which the adhesive sheet is bonded is mounted on a table at 60 to 150 ° C to bring the adhesive sheet into contact with a table, and is heated by adsorption and fixation. And inspecting the semiconductor wafer or the semiconductor component; and irradiating the photocurable adhesive layer of the adhesive sheet with activating light; and expanding the film to stretch the space between the semiconductor wafer or the semiconductor component The adhesive sheet; a picking step of picking up the semiconductor wafer or the semiconductor component from the adhesive sheet.

Here, the "tackifying resin" includes a resin previously mixed to improve the viscosity of the acrylic adhesive, such as rosin resin, terpene resin, aliphatic petroleum resin, aromatic petroleum resin, hydrogenated petroleum resin, benzene. And a furan-indene resin, a styrene resin, a xylene resin, a mixture of the resins, and the like.

According to the present invention, there is provided an adhesive sheet which is hard to produce softening of an adhesive layer upon heating.

Hereinafter, preferred embodiments of the present invention will be described. Further, the embodiments described below show an example of a representative embodiment of the present invention, and the explanation of the scope of the present invention is not so narrow.

Adhesive sheet

(1) Light curing adhesive

(1-1) tackifying resin

(1-2) (meth) acrylate copolymer

(1-3) Photopolymerizable compound

(1-4) Polyfunctional isocyanate curing agent

(1-5) Photopolymerization initiator

(2) Substrate

2. Method of manufacturing electronic parts

(1) Fitting process

(2) Heating process

(3) Cutting process

(4) Light (ultraviolet light) irradiation process

(5) Extension. Picking process

Adhesive sheet

In the adhesive sheet of the present invention, a photocurable adhesive layer (hereinafter also referred to simply as "adhesive layer") is laminated on the substrate, and the tackifier is not contained in the adhesive. The adhesive of the present invention does not cause softening of the adhesive layer due to softening of the tackifying resin even when heated, and therefore does not excessively adhere to the semiconductor wafer or the like. Therefore, in the adhesive sheet of the present invention, the adhesion of the adhesive layer can be sufficiently reduced by irradiation with ultraviolet rays or the like, and pickup defects and adhesive deposits can be prevented.

(1) Light curing adhesive

The photocurable adhesive forming the adhesive layer of the adhesive sheet of the present invention comprises a (meth) acrylate copolymer, a photopolymerizable compound, and a polyfunctional The cyanate curing agent and the photopolymerization initiator do not contain a tackifying resin.

(1-1) tackifying resin

The tackifier resin which causes softening of the adhesive layer during heating is not particularly limited, and examples thereof include rosin resins, terpene resins, aliphatic petroleum resins, aromatic petroleum resins, hydrogenated petroleum resins, benzofuran-indene resins, and the like. A styrene resin, a xylene resin, and a mixture of such resins.

As long as the tackifier resin is not contained in the adhesive, various additives such as a peeling enhancer, an anti-aging agent, a filler, an ultraviolet ray absorbing agent, and a light stabilizer may be added. Among the peeling enhancers, for example, a polyfluorene-based graft copolymer can be used.

(1-2) (meth) acrylate copolymer

The (meth) acrylate copolymer is only a polymer of a (meth) acrylate monomer or a copolymer of a (meth) acrylate monomer and a vinyl compound monomer. Further, (meth) acrylate means a general term for acrylate and methacrylate. Similarly, a compound containing a (meth) acrylate (meth) acrylate or the like is a generic term for a compound containing a "methyl group" in the name and a compound not including a "methyl group".

Examples of the monomer of the (meth) acrylate include butyl (meth)acrylate, butyl 2-(meth)acrylate, butyl t-(meth)acrylate, and amyl (meth)acrylate. Octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, (meth)acrylate Ester, ethyl (meth)acrylate, isopropyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, (methyl) Octadecyl acrylate, (meth) propyl Cyclohexyl enoate, isodecyl (meth) acrylate, dicyclopentanyl (meth) acrylate, benzyl methacrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate , butoxymethyl (meth)acrylate and propyl ethoxy-n-(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, ( 4-hydroxybutyl methacrylate.

Examples of the vinyl compound monomer copolymerizable on the (meth) acrylate monomer include a functional group-containing monomer containing one or more carboxyl groups, an epoxy group, a decylamino group, an amine group, a hydroxymethyl group, and a sulfonate. A functional group such as an acid group, a sulfamic acid group or a sulfonate group.

As the monomer having a carboxyl group, for example, (meth)acrylic acid, crotonic acid, maleic acid, anhydrous maleic acid, methylene succinic acid, fumaric acid, acrylamido-N-glycolic acid And cinnamic acid.

Examples of the monomer having an epoxy group include propenyl propyl triether ether and (meth)acrylic acid epoxy propyl ether.

As the monomer having a guanamine group, for example, (meth) acrylamide.

As the monomer having an amine group, for example, N-N-dimethylamine ethyl acrylate is used.

As the monomer having a methylol group, for example, N-methylol acrylamide can be used.

(1-3) Photopolymerizable compound

As the photopolymerizable compound, for example, trimethylolpropane triacrylate, neopentyltetraol tetraacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, or the like can be used. Polydipentaerythritol hexaacrylate, 1,4-butanediol diacrylate, 1,6 hexanediol diacrylate, polyethylene glycol diacrylate, triethyl acrylate Ester, commercially available oligomeric acrylate, and the like.

As the photopolymerizable compound, in addition to the above acrylate compound, an urethane acrylate oligomer can also be used. An urethane oligo-polymer system having a hydroxyl group on a terminal isocyanate urethane prepolymer obtained by reacting a polyester compound with a polyether-type polyvalent alcohol compound and a polyvalent isocyanate compound Base) acrylate derived.

Among the polyvalent isocyanate compounds, for example, 2,4-tolyl diisocyanate, 2,6-tolyl diisocyanate, 1,3-diisocyanate, 1,4-diisocyanate can be used. Xylene ester, 4,4-diphenylmethane diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the like. Further, among the (meth) acrylate having a hydroxyl group, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or polyethylene glycol (meth)acrylic acid can be used. Ester, pentaerythritol triacrylate, propylene glycol di(meth) acrylate, dipentaerythritol monohydroxy pentoxide, and the like.

As the photopolymerizable compound, an urethane acrylate oligomer having four or more vinyl groups is preferred, and the adhesive after irradiation with ultraviolet ray or the like is well cured.

The amount of the photopolymerizable compound is preferably 5 parts by mass or more and 200 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer. When the amount of the photopolymerizable compound is reduced, the peeling property of the adhesive sheet after irradiation with radiation is lowered, and the pickup failure of the semiconductor wafer is likely to occur. On the other hand, if the amount of the photopolymerizable compound is increased, picking up due to the sticking of the adhesive during cutting is liable to cause picking failure, and The reaction residue produces tiny deposits of adhesive that cause contamination.

(1-4) Polyfunctional isocyanate curing agent

Among the polyfunctional isocyanate curing agents, those containing two or more isocyanate groups, for example, aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, such dimers and trimers, adducts and the like are used.

Examples of the aromatic polyisocyanate include 1,3-benzene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and 2,4-. Tolyl diisocyanate, 2,6-tolyl diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-tolyl isocyanate, 1,3,5-tolyl isocyanate benzene, dianion amine Isocyanate, 4,4'-diphenyl ether diisocyanate, 4,4',4"-triphenylmethane tolyl isocyanate, ω,ω'-diisocyanate-1,3-xylene, ω,ω'-diisocyanate -1,4-xylene, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylbenzenedimethylene diisocyanate, and 1,3-tetramethylbenzene dimethylene Diisocyanate.

As the aliphatic polyisocyanate, for example, propyl diisocyanate, butyl diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propyl diisocyanate, 2,3-butene Diisocyanate, 1,3-butene diisocyanate, dodecamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate.

As the alicyclic polyisocyanate, for example, 3-isocyanatomethyl 3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1 , 4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexane isocyanate), 1,4-bis(cyclohexane isocyanate)cyclohexane and 1,4- Bis(isocyanatemethylene)cyclohexane.

Examples of dimers and trimers and adducts include dimers of diphenylmethane diisocyanate, trimer of hexamethylene diisocyanate, and addition of trimethylolpropane and tolyl diisocyanate. An adduct of trimethylolpropane and hexamethylene diisocyanate.

Among the above polyisocyanates, it is preferred to have three or more isocyanate groups, and particularly preferred is a trimer of hexamethylene diisocyanate, an adduct of trimethylolpropane and tolyl diisocyanate, and a trimethylol group. An adduct of propane with hexamethylene diisocyanate.

The mixing ratio of the polyfunctional isocyanate curing agent is preferably 0.5 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer, and more preferably 1.0 parts by mass or more and 10 parts by mass. The following. When the polyfunctional isocyanate curing agent is 0.5 parts by mass or more, the adhesive force is not excessively strong, so that occurrence of pickup failure can be suppressed. When the polyfunctional isocyanate curing agent is 20 parts by mass or less, the adhesive force is not lowered, and the retention of the semiconductor wafer can be maintained at the time of dicing.

(1-5) Photopolymerization initiator

Among the photopolymerization initiators, benzoin, benzoin aryl ethers, acetophenones, onion peptides, ketoxines, ketals, diphenylketones or xanthones can be used.

Examples of the benzoin include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin dipropyl ether and the like.

As the acetophenones, for example, benzoin aryl ethers, acetophenone, 2,2-dimethoxy-2-acetophenone, 2,2-diethoxy-2-acetophenone, 1, 1-dichlorobenzene Ethyl ketone and the like.

Examples of the onion peptides include 2-methylhydrazine, 2-ethylhydrazine, 2-tert-butylhydrazine, 1-chloroindole and the like.

Examples of the ketoxines include 2,4-dimethyl ketoxime, 2,4-diisopropyl ketoxime, 2-chloroseptone, 2,4-diisopropyl ketoxime, and the like. .

Examples of the ketals include acetophenone dimethyl ketal, benzyl dimethyl ketal, benzyl diphenyl sulphide, tetramethyl thiuram monosulfide, azobisisobutyronitrile, and Phenyl, diacetyl, β-chloropurine and the like.

The photopolymerization initiator is heated from a temperature of 23 ° C to a temperature increase rate of 10 ° C / min to 500 ° C, and a mass loss rate of 10% is preferably 250 ° C or more. When the adhesive sheet bonded to the wafer or the like is heated to 60 to 150 ° C in the heating step described later, if the photopolymerization initiator is volatilized or deteriorated, the adhesive layer is cured in the subsequent step, that is, in the light irradiation step. Insufficient, the adhesion cannot be sufficiently reduced, which is the main cause of poor pickup in the subsequent picking process. Therefore, it is preferred to use a photopolymerization initiator which has the above-described properties and is less likely to cause volatilization and deterioration upon heating.

As the photopolymerization initiator having a temperature of 250 ° C or higher, ethyl ketone, 1-[9-ethyl-6-(2-toluamyl)-9H-carbazol-3-yl]-, 1 -(O-Ethyl hydrazine) (manufactured by BASF JAPAN, product name IRGACURE OXE02), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (manufactured by BASF JAPAN, product name LUCIRIN TPO And 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propenyl)-benzyl]-phenyl}-2-methyl-propan-1-one (BASF) Manufactured by JAPAN, product name IRGACURE127), 2-phenyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1 (BASF JAPAN Manufactured by the company, product name IRGACURE 369), 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (manufactured by BASF JAPAN, product name IRGACURE 379), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (manufactured by BASF JAPAN, product name: IRGACURE 819).

Among them, especially the above-mentioned temperature is 270 ° C or more of ethyl ketone, 1-[9-ethyl-6-(2-toluamyl)-9H-carbazol-3-yl]-, 1-(O- Ethyl acetate (manufactured by BASF JAPAN, product name IRGACURE OXE02), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (manufactured by BASF JAPAN, product name LUCIRIN TPO) and 2- Hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propenyl)-benzyl]-phenyl}-2-methyl-propan-1-one (manufactured by BASF JAPAN, Product name IRGACURE127) is preferred.

The amount of the photopolymerization initiator to be added is preferably 0.1 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the (meth) acrylate polymer. When the amount of the mixture is too small, the peeling property of the adhesive sheet after irradiation with radiation is lowered, and the pickup failure of the semiconductor wafer is likely to occur. On the other hand, if the amount of the mixture is too large, the photopolymerization initiator flows to the surface of the adhesive to cause contamination.

In the photopolymerization initiator, one or two kinds of previously known photopolymerization accelerators may be used in combination as needed. Among the photopolymerization accelerators, benzoic acid, tertiary amine, and the like can be used. Examples of the tertiary amine include triethylamine, tetraethylenepentamine, dimethylamine ether and the like.

The thickness of the adhesive layer is preferably from 3 μm to 100 μm, particularly preferably from 5 μm to 20 μm. If the adhesive layer is too thick, the adhesion will become Too high, the pickup is reduced. Further, when the adhesive layer is too thin, the adhesive force is too low, and the wafer retainability at the time of dicing is lowered, and peeling may occur between the annular frame and the sheet.

(2) Substrate

Examples of the material of the substrate include polyvinyl chloride, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-acrylic acid-acrylate film, ethylene-ethyl acrylate copolymer, and polyethylene using metal ions. , polypropylene, propylene copolymer, ethylene-acrylic acid copolymer, and ethylene-(meth)acrylic acid copolymer and ethylene-(meth)acrylic acid-(meth)acrylate copolymer, etc. . The substrate may be a mixture or a copolymer of the resins, or may be a laminate of a film and a sheet composed of the resins.

Among the materials of the substrate, a propylene-based copolymer is preferably used. A propylene-based copolymer having good heat resistance and extensibility is used as a material, and it can be obtained that it does not cause softening and melting even when heated, does not cause shrinkage, and can be expanded. An adhesive sheet that is sufficiently stretched in the picking process.

Examples of the propylene-based copolymer include a random copolymer of propylene and other components, a block copolymer of propylene and other components, and an alternating copolymer of propylene and other components. As other components, there are an α-olefin such as ethylene, 1-butene, 1-pentene, 1-hexene or 1-heptene, a copolymer composed of at least two or more α-olefins, and a styrene-diene copolymer. Things and so on.

Among the propylene-based copolymers, a copolymer of propylene with 1-butene and ethylene is preferred. A copolymer of propylene and 1-butene and ethylene has flexibility in addition to heat resistance, so that it can be expanded by using it. Good adhesion to the sheet.

The substrate may be a single layer or a plurality of layers or sheets composed of the foregoing materials, or may be a film composed of different materials. The thickness of the substrate is 50 to 200 μm, preferably 70 to 150 μm.

For the substrate, it is preferred to carry out static electricity prevention treatment. As the static electricity prevention treatment, there is a treatment of adding an antistatic agent to the substrate, a treatment of applying an antistatic agent to the surface of the substrate, and a treatment by corona discharge.

As the antistatic agent, for example, a quaternary amine salt monomer or the like can be used. Examples of the quaternary amine salt monomer include dimethylamine ethyl ester tetrachloride, diethylamine ethyl ester tetrachloride, methyl ethylamine methacrylate tetrachloride, and p-dimethylamine. Styrene quaternary chloride and p-diethylamine styrene quaternary chloride. Among them, dimethylamine ethyl ester tetrachloride is preferred.

2. Method of manufacturing electronic parts

The method for producing an electronic component according to the present invention includes the step of heating the electronic component to which the adhesive sheet is bonded to 60 to 150 °C. Hereinafter, specific steps of the manufacturing method will be sequentially described. However, the term "electronic component" as used in the present invention means a semiconductor wafer, a substrate, a semiconductor wafer, a semiconductor component, or the like.

(1) Fitting process

First, in the bonding step, the adhesive sheet is bonded to the semiconductor wafer (or substrate) and the annular frame. Wafers can be wafers and previously used wafers such as gallium nitride wafers, tantalum carbide wafers, and sapphire wafers.

(2) Heating process

In the case of performing a circuit test formed on a wafer or the like, after the bonding step, the wafer or the like is heated at about 60 to 150 ° C for about 15 minutes to 5 hours. specific In other words, the semiconductor wafer or substrate to which the adhesive sheet is attached is mounted on a table at 60 to 150 ° C to bring the adhesive sheet into contact with the table, heat by adsorption, and inspect the semiconductor wafer or substrate. . Moreover, in the case where the test of the circuit is performed after the semiconductor wafer or the semiconductor component is obtained, the heating process is performed in the same manner after the dicing process described below. That is, the semiconductor wafer or the semiconductor component to which the adhesive sheet is bonded is placed on a table at 60 to 150 ° C to bring the adhesive sheet into contact with the stage, and is heated by adsorption and fixation, and the semiconductor wafer or the semiconductor component is inspected. Further, the heating step is carried out for the purpose of removing the cutting water after the dicing step, and the semiconductor wafer or the like is heated at about 60 to 150 ° C for about 15 minutes to 5 hours.

The adhesive sheet of the present invention does not excessively adhere to a semiconductor wafer or the like because it does not cause softening of the adhesive layer due to softening of the tackifying resin even when heated. Therefore, in the method of producing an electronic component according to the present invention, in the ultraviolet ray irradiation step and the pickup step which will be described later, the adhesion of the adhesive layer can be sufficiently reduced by irradiation with ultraviolet ray or the like, and pickup defects and adhesive deposits can be prevented.

(3) Cutting process

In the dicing process, a germanium wafer or the like is diced to form a semiconductor wafer or a semiconductor component. After the dicing step, the heating step may be performed for the purpose of removing cutting water.

(4) Lighting process

In the light irradiation process, the photocurable adhesive layer is irradiated with an active light such as ultraviolet ray from the substrate side. As the light source of the ultraviolet ray, a low pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, or a metal halide lamp can be used. Also, An electron beam is used instead of the ultraviolet ray, and as a light source of the electron beam, α缐, β缐, γ缐 can be used.

The adhesive layer is solidified by three-dimensional reticulation by light irradiation, and the adhesion of the adhesive layer is lowered. At this time, as described above, the adhesive sheet of the present invention does not excessively adhere to the wafer or the like even if it is heated, so that the adhesion can be sufficiently reduced by irradiation with ultraviolet rays or the like.

(5) Extension. Picking process

In the expansion. In the pick-up process, in order to widen the interval between the semiconductor wafer or the semiconductor component, the adhesive sheet is stretched, and the wafer or the component is lifted upward by a pin or the like. Then, the wafer or the part is adsorbed by a vacuum collet or air tweezers, and the adhesive layer of the adhesive sheet is peeled off and picked up. At this time, in the adhesive sheet of the present invention, sufficient adhesion is reduced by irradiation with ultraviolet rays or the like, so that peeling between the wafer or the part and the adhesive layer becomes easy, and good pickup property is obtained. It also does not cause defects such as adhesive deposits.

After the picking process, the picked wafer or part is loaded into the lead frame via the die attach sealant. After being mounted, the heated die attaches the sealant and heats the bonded wafer or part to the lead frame. Then, the wafer or the component mounted on the lead frame is molded by a resin.

[Examples] <Example 1>

The photocurable adhesive was prepared according to the mixing shown in "Table 1". The photocurable adhesive was applied onto a separator film made of polyethylene terephthalate, and the thickness of the adhesive layer after drying was applied to 10 μm. Adhesive layer The substrate film was aged at 40 ° C for 7 days to obtain an adhesive sheet. In the base film (K-1), a propylene-based copolymer (part: X500F) manufactured by Nippon Monterey Showa Co., Ltd. was formed into a film of 80 μm by T-type extrusion.

[Substrate film]

K-1: a propylene copolymer (part number: X500F) manufactured by Monta Showa Co., Ltd., Japan; propylene and 1-butene and ethylene are contained as a polymerization component, and the MFR (melt index) is 7.5 g/10 min. The density is 0.89 g/cm ³ .

K-2: a propylene copolymer (part number: Q300F) manufactured by Monta Showa Co., Ltd.; propylene and ethylene are contained as a polymerization component, and have an MFR value of 0.9 g/10 min and a density of 0.89 g/cm ³ .

K-3: an ethylene-based copolymer (part number: synthetic vinyl resin 537) manufactured by Japan Toyo Soda Co., Ltd., a vinyl acetate content of 6%, an MFR value of 8.5 g/10 minutes, and a density of 0.93 g/cm ³ .

K-4: Low density polyethylene (part number: Petrothene 170) manufactured by Toyo Soda Industrial Co., Ltd., MFR value of 1.0 g/10 min, and density of 0.92 g/cm ³ .

[Photocurable adhesive] [(Meth)acrylate copolymer]

A-1: Acrylic rubber AR53L manufactured by Zeon Co., Ltd.; obtained by emulsion polymerization of a copolymer of 54% ethyl acrylate, 19% butyl acrylate, and 24% methoxyethyl acrylate.

A-2: SK-Dyne 1496 manufactured by Soken Chemical Co., Ltd.; can be obtained by solution polymerization of a copolymer of 2-ethylhexyl acrylate 96% and 2-hydroxyethyl acrylate 4%.

[Photopolymerizable compound]

B-1: UN-905 manufactured by Gensei Kogyo Co., Ltd.; it is mainly reacted with dipentaerythritol pentaacrylate in the terpolymer of isophorone diisocyanate. The acrylate of the component was obtained, and the number of vinyl groups was 15.

B-2: A-TMPT manufactured by Shin-Nakamura Chemical Co., Ltd.; the number of trimethylolpropane triacrylate and vinyl is 15.

[Polyfunctional isocyanate curing agent]

C-1: CORONATE L-45E manufactured by Nippon Polyurethane Industry Co., Ltd.; trimethylolpropane adduct of 2,4-tolyl diisocyanate.

C-2: propyl diisocyanate.

[Photopolymerization initiator]

D-1: IRGACURE OXE02 manufactured by BASF JAPAN; ethyl ketone, 1-[9-ethyl-6-(2-toluamyl)-9H-carbazol-3-yl]-, 1-(O- The temperature at which the mass loss rate is 10% is 320 ° C.

D-2: LUCIRIN TPO manufactured by BASF JAPAN Co., Ltd.; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and the temperature at a mass loss rate of 10% was 270 °C.

D-3: IRGACURE127 manufactured by BASF JAPAN; 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propenyl)-benzyl]-phenyl}-2- The base-propan-1-one and the mass loss rate of 10% were 275 °C.

D-4: IRGACURE 651 manufactured by BASF JAPAN Co., Ltd.; a diphenylmethyl ketal having a temperature loss rate of 185 ° C at a mass loss rate of 10%.

[Polyoxygenated graft copolymer]

E-1: UTMM-LS2 manufactured by Soken Chemical Co., Ltd.; polymerized at the end of the polyoxyl molecular chain by a polyoxyl oxy group unit having a (meth) acrylonitrile group and methyl methacrylate A polyoxymethylene graft copolymer of ethylene acrylate units.

[Tackifying Resin]

F-1: YS POLYSTAR S145 manufactured by Anwara Chemical Co., Ltd.; terpene phenolic tackifying resin having a softening point of 145 °C.

The obtained adhesive sheet was bonded to a tantalum wafer and an annular frame having a diameter of 8 inches and a thickness of 0.1 mm which were formed into a virtual circuit model, and cut. The silicon wafer is placed on the heating plate, and the bonding surface of the adhesive sheet is brought into contact with the opposite side surface. After heating at 120 ° C for 1 hour, light irradiation and expansion are carried out. Pick up the various processes.

The conditions of the cutting process are as follows.

Cutting device: DAD341 manufactured by DISCO

Cutting board: NBC-ZH205O-27HEEE manufactured by DISCO

Cutting plate shape: outer diameter 55.56 mm, tooth width 35 μm, inner diameter 19.05 mm.

Cutting board speed: 40,000 rpm

Cutting board feeding speed: 50mm / sec

Cutting size: 10mm angle

Cutting depth for adhesive sheets: 15μm

Cutting water temperature: 25 ° C

Cutting water volume: 1.0 l / min

The conditions of the light irradiation process are as follows.

Ultraviolet 缐 irradiation: The irradiation amount using a high pressure mercury lamp was 150 mJ/cm ² .

Expansion. The conditions of the picking process are as follows.

Pickup device: CAP-300II manufactured by Canon Machinery Co., Ltd.

Expansion amount: 8mm

Pin shape: 250μmR

Number of pins: 5

Pin top height: 0.3mm

In the cutting process and expansion. In the picking up process, the following evaluation was performed.

(1) Wafer retention

With respect to wafer retention, after the dicing process, the residual rate of the semiconductor wafer fixed on the adhesive sheet by the semiconductor wafer was evaluated by the following criteria.

Excellent: less than 5% wafer movement

Good: wafer movement is 5% or more and 10% or less

No: the wafer movement is more than 10%

(2) Picking property

For the pick-up property, in the pickup process, based on the ratio at which the semiconductor wafer was picked up, evaluation was performed by the following criteria.

Excellent: The chip picking success rate is over 95%

Good: The chip picking success rate is 80% or more and 95% or less.

No: the chip picking success rate is less than 80%

The evaluation results are shown in [Table 1]. In the adhesive sheet of Example 1, both wafer retainability and pick-up property were evaluated as excellent.

<Examples 4 and 5, Reference Examples 1 to 8>

In addition to the material of the base film, the (meth) acrylate copolymer, and the photopolymerizable compound, the polyfunctional isocyanate curing agent, the photopolymerization initiator, the polyfluorene-based graft copolymer, or the presence or absence of addition, In the same manner as in Example 1, an adhesive sheet was produced and carried out in the same manner as in the above-described modification. Evaluation. The results are shown in Table 1.

<Examples 13 to 17, Reference Examples 9 to 12>

The adhesive sheet obtained by the same method as in Example 1 was bonded to a tantalum wafer and an annular frame having a diameter of 8 inches and a thickness of 0.1 mm which were formed into a virtual circuit model, and was cut. The tantalum wafer was placed on a heating plate, and the adhesive sheet bonding surface was brought into contact with the opposite side surface. After heating under the conditions shown in [Table 1], light irradiation and expansion were carried out under the same conditions as in Example 1. Pick up the various processes. The results are shown in Table 1.

<Comparative Example 1>

An adhesive sheet was produced and evaluated in the same manner as in Example 1 except that the polyoxymethylene graft copolymer was not added, except that the tackifier resin was added. The results are shown in Table 1.

In Examples 4, 5, 13 to 17, and Reference Examples 1 to 12, good wafer retention and pick-up properties were ensured. On the other hand, in Comparative Example 1, the pick-up property was poor and the adhesive deposit was also remarkable.

[Industrial availability]

In the adhesive sheet of the present invention, since the adhesive layer is not softened even when heated, it does not excessively adhere to the semiconductor wafer or the like, so that the adhesive layer can be sufficiently reduced by irradiation with ultraviolet rays or the like. The adhesion is good and the pick-up is good. Therefore, in the semiconductor wafer processing step, the adhesive sheet of the present invention can be preferably used in a performance test or a dicing step of forming a semiconductor wafer or the like to include a heating process for removing cutting water. situation.

Claims (6)

An adhesive sheet comprising a photocurable adhesive layer comprising the (meth) acrylate copolymer, wherein the photocurable adhesive layer is formed by laminating a photocurable adhesive layer on a substrate. a photopolymerizable compound, a polyfunctional isocyanate curing agent, a polyfluorene-based graft copolymer, and a photopolymerization initiator, which do not contain a tackifying resin, and the above substrate is formed of a propylene-based copolymer which is propylene. a copolymer of 1-butene and ethylene, the above (meth) acrylate copolymer is a copolymer of ethyl (meth) acrylate, butyl (meth) acrylate and methoxy ethyl (meth) acrylate The polyfunctional isocyanate curing agent contains three or more isocyanate groups, and when the photopolymerization initiator is heated at a temperature increase rate of 10 ° C /min from 23 ° C to 500 ° C, the temperature loss rate is 10% and the temperature is 250 ° C or higher. The photopolymerizable compound is an urethane acrylate oligomer having four or more vinyl groups, and the photopolymerizable compound is contained in an amount of 5 parts by mass or more and 200 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer. , the above polyfunctional The cyanate curing agent is 0.5 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer, and the photopolymerization initiator is 0.1 part by mass based on 100 parts by mass of the (meth) acrylate copolymer. More than 20 parts by mass or less. The adhesive sheet of claim 1 is used by being attached to the electronic component in the inspection process of the electronic component. An adhesive for forming an adhesive layer laminated on a substrate in an adhesive sheet attached to the electronic component in an inspection process of an electronic component, comprising: (meth) acrylate copolymerization a material, a photopolymerizable compound, a polyfunctional isocyanate curing agent, a photopolymerization initiator, and a polyfluorene-based graft copolymer, which do not contain a tackifier resin, and the substrate is formed of a propylene-based copolymer, and the propylene-based copolymer is Copolymer of propylene, 1-butene and ethylene, copolymerization of the above (meth) acrylate copolymer with ethyl (meth) acrylate, butyl (meth) acrylate and methoxy ethyl (meth) acrylate The polyfunctional isocyanate curing agent contains three or more isocyanate groups, and when the photopolymerization initiator is heated at a temperature increase rate of 10 ° C /min from 23 ° C to 500 ° C, the temperature loss rate is 10% and the temperature is 250 ° C. In the above, the photopolymerizable compound is an urethane acrylate oligomer having four or more vinyl groups, and the photopolymerizable compound is contained in an amount of 5 parts by mass or more and 200 parts by mass based on 100 parts by mass of the (meth) acrylate copolymer. Below, the above The amount of the isocyanate curing agent is 0.5 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer, and the photopolymerization initiator is 0.1 parts by mass based on 100 parts by mass of the (meth) acrylate copolymer. More than 20 parts by mass or less. A method for producing an electronic component, comprising: a heating step of heating an electronic component to which an adhesive sheet is bonded to 60 to 150° C., wherein the adhesive sheet is laminated on a substrate and cured by light curing. An adhesive sheet formed of an adhesive layer formed of a propylene-based copolymer which is a copolymer of propylene, 1-butene and ethylene, and forms a photocurable layer of the photocurable adhesive layer The adhesive includes a (meth) acrylate copolymer, a photopolymerizable compound, a polyfunctional isocyanate curing agent, a photopolymerization initiator, and a polyfluorene-based graft copolymer, and does not contain a tackifying resin, and the above (meth) The acrylate copolymer is a copolymer of ethyl (meth)acrylate, butyl (meth)acrylate and methoxyethyl (meth)acrylate, and the polyfunctional isocyanate curing agent contains three or more isocyanate groups, and the above When the photopolymerization initiator is heated at a temperature increase rate of 10 ° C /min from 23 ° C to 500 ° C, the temperature loss rate is 10% and the temperature is 250 ° C or higher, and the photopolymerizable compound is an acrylic acid having four or more vinyl groups. An amine ester oligomer, and the photopolymerizable compound is 5 parts by mass or more and 200 parts by mass or less based on 100 parts by mass of the (meth) acrylate copolymer, and the above polyfunctional isocyanate curing agent is copolymerized with respect to (meth) acrylate. 100 quality 20 parts by mass 0.5 parts by mass or more lines or less, the photopolymerization initiator with respect to 20 parts by mass of (meth) acrylic acid ester copolymer 100 parts by mass 0.1 part by mass or less based. The method of manufacturing an electronic component according to claim 4, comprising: a bonding step of bonding the adhesive sheet to a semiconductor wafer or a substrate and an annular frame; and a heating step of bonding the adhesive sheet The semiconductor wafer or substrate is mounted on a workbench at 60~150 °C to make the adhesive sheet work. The semiconductor phase is contacted, heated by adsorption and inspection, and the semiconductor wafer or substrate is inspected; and the dicing process is performed by cutting the semiconductor wafer or substrate to which the adhesive sheet is attached to form a semiconductor wafer or a semiconductor component; And irradiating the photocurable adhesive layer of the adhesive sheet with activating light; the expanding step of stretching the adhesive sheet by widening the interval between the semiconductor wafer or the semiconductor component; and the picking step from the adhesive sheet The semiconductor wafer or semiconductor component is picked up. A method of manufacturing an electronic component according to claim 4, comprising: a bonding step of bonding the adhesive sheet to a semiconductor wafer or a substrate and an annular frame; and a cutting step of attaching the adhesive sheet After the semiconductor wafer or the substrate is diced, the semiconductor wafer or the semiconductor component is formed; and the heating process is performed, and the semiconductor wafer or the semiconductor component to which the adhesive sheet is bonded is mounted on a workbench at 60 to 150 ° C to bond the sheet and the workbench. Contacting, heating by adsorption fixation, and inspecting the semiconductor wafer or semiconductor component; illumination process, irradiating the photocurable adhesive layer of the adhesive sheet with activating light; expanding step of widening the semiconductor wafer or The adhesive sheet is stretched by a space between the semiconductor parts; and a pick-up process is performed to pick up the semiconductor wafer or the semiconductor component from the adhesive sheet.